closes #9, adding http_client_options
Merge pull request #10 from marcelog/marcelog_http_client_options_9

closes #9, adding http_client_options
Change dependencies' protocol from git to https

Some servers behind firewall will only support http/https but not git
protocol due to company security policy
Merge pull request #11 from bluesalt/dep_protocol

Change dependencies' protocol from git to https
hackney:request can also return {error, ...}
Merge pull request #12 from arjan/master

hackney:request can also return {error, ...}
returning elasticsearch errors

so the caller would know what went wrong
Merge pull request #13 from marcelog/marcelog_returning_elasticsearch_errors

returning elasticsearch errors
allowing payload for methods like DELETE.

In its delete_by_query api, elasticsearch allows the query to
be passed in the query string, but also as a json payload. This
should allow that, and also does some cleanup, by treating the
absence of a payload as a payload of 0 size (content-length)
Merge pull request #14 from marcelog/marcelog_delete_by_query_with_body

allowing payload for methods like DELETE.